Serious medication errors are common after hospital discharge and cause significant patient morbidity. Errors are more common among patients taking cardiovascular medications and may also be more common among patients with low health literacy. On the other hand, patients with low health literacy may benefit more than other patients from interventions designed to improve knowledge and skills. The objective of this research is to reduce the incidence of serious medication errors during the first 30 days after hospital discharge among patients hospitalized with acute coronary syndromes (ACS) or heart failure (HF) exacerbation. We will conduct a randomized controlled trial of a literacy-sensitive, pharmacist-based intervention in 862 patients discharged from the general medicine service at two academic medical centers: Emory University/Grady Memorial Hospital (GMH) and Brigham and Women's Hospital (BWH). The study will have two arms: 1) Usual Care: pharmacists performing only routine evaluations of medication orders, physicians performing medication reconciliation, and nurses providing medication counseling at discharge;and 2) Intervention: pharmacist assistance with medication reconciliation, pharmacist counseling of patients at the time of discharge, provision of a literacy-sensitive patient education tool detailing the discharge medications, and a follow-up phone call 1-2 days later and subsequently if needed. Randomization will occur at the level of the patient. The primary outcome will be the percent of patients with at least one serious medication error within 30 days after hospital discharge. Serious medication errors consist of: 1) actual adverse drug events (ADEs) that could have been prevented (preventable ADEs), 2) actual ADEs that could have been reduced in severity or duration (ameliorable ADEs), and 3) medication discrepancies or non- adherence with the potential to cause adverse events (potential ADEs). Adjudication of serious medication errors will be performed by two independent physicians blinded to study assignment. Subgroup analyses will be performed by level of health literacy to determine if patients with inadequate health literacy are more likely to benefit from the intervention. Program costs will also be assessed. If successful, this intervention could offer an important means of reducing medication errors in the post-hospitalization period.